Hola Guys

[Scope]

phewwwww.... That was a close one... Almost made my first post in the how-to section. Well Hello guys, I hate to make my first post a question but yea I'm going to.

Alright my "to be" project is going to be a duel chamber pneumatic, both with there own valves and fills/guages... This will hopefully allow for me to utalize (sp) my compressor (wimpy) the most. The design will be similar to Joels duel tanks cannons, minus the supahs(to much $$$, and to stupid to make my own).

Alright well first off does everyone think that will be a good design. I have not run it through the GGDT due to my lack of knowledge of all the perametors(sp again).

Also what are your ideas for a valve (deff not ball valves or unmoded sprinklers) . I need something good and cheap (sounds like everything in life). What would be my options, possibly like a quick exhaust valve or something. I sorta wanna stay away from the idea of a piston valve because I dont have the experiance for that. So I wanna go with either a modded sprinkler, a quick exhaust(like boogies http://www.advancedspuds.com/gbcannon.htm ) or any other ideas you guys have...I plan on linking the 2 valves together on one pilot so that i can release them together.

Wow that was a mouthfull!
Thank you anyone that responds. I have put alota thought into this design and i want it to be perfect.

[ProfessorAmadeus]

Go with the QEV for sure. The designs sounds good and i dont like GGDT becasue it just alot more fun to you know.... SHOOT IT!!!

[Scope]

Yea that what I really wanted to do... but im lost where to get them and what ones can be addapted... I know boogie got his of ebay... but i couldn't find anything there.

[nicholai]

Look around online for a 3/4" 90 deg. quick exhaust valve, mcmaster.com has a good one (part number 6646k23) for $20, its better than a 1" modified sprinkler valve, and it works virtually the same

[Scope]

Thank you so much. That was what I was looking for.
Will I be able to putting a airgun release on that?

[nicholai]

absolutly, the ass end of a blowgun is 3/8" NPT, the quick exhaust valve is 3/4" NPT. You will need a 3/4" to 3/8" flush bushing to connect them directly, but you will want to buy a tee to connect the blowgun and a schrader or quick disconnect, or both (to pressurize it) feel free to send me a private message if you have any more questions

the easiest way to do it is to attach the flush bushing onto the pilot (fill and trigger) side of the valve, then the ass end of the blowgun, then a schrader valve to fill with a tire chuck, you will have to hold the blowgun down to fill it, release it, then disconnect the air source, then hit the blowgun again to trigger the valve

[Scope]

So I put a schrader in each tank.
then buy hose, a tee, and all the connectors to connect the threaded peices to the valve/airgun. That way i can run 1 pilot into 2 valves.

Another question if i have 2 seperatly charged tanks limited by 3/4 airflow by the valves, could i make the pvc tee (right infront of barrel) a 1.5 inch tee..
that way i get both tanks gettin the max imput without having to slow down to compete with eachother, or on the other hand does the 2 tanks having to compress into one 3/4 space maximize the psi on launch...
Im not smart when it comes 2 the fluid dynamics stuff does anyone have an idea what Im trying to say.

[nicholai]

unless you want to go really big you shouldnt really have to worry about the air flow choking from the QEV's 3/4" outlet. If you want to make a huge cannon like joels mega launcher you are going to need a pair of piston valves. If you wanted to make a smaller version the QEV's will be fine up to a certain point. What did you have in mind for air chamber size and barrel size?

[Scope]

The chambers most likely 2ish long with 4inch pipe.
Barrel most likely a 3 inch(thats common right?)

[nicholai]

id suggest a 2" barrel, but you could simply use threaded fittings for interchangable barrels

[SpudStuff]

With the 2 x 3/4" valves at ~$20 each I would reccomend a 2" Sprinkler valve. The cheapest ones are $50, but you will get higher flow and similar opening time.

Also, with the 2" valve you will need less fittings to connect to the chamber and barrel and there for less fluid friction. This will increase power. Also these 2" valves are rated to a higher pressure then the 3/4" QEVs.

[Scope]

That will allow me to go with a less complicated release 2 but i would have to add ball valves the single out the chambers...

[SpudStuff]

Ummm... No, no you wouldn't... You want to make a dual chamber? Then just use a tee and elbows to combind them. The valve only needs a blowgun (perferably high flow) to modify it. The part that really matters id the dead space and restriction AFTER the valve on the barrel size.

[Scope]

No i mean to be able to seperate the two tanks i kno you can have 2 tanks with just a tee but then when you pressurize one you pressurize the other
i wanna be able 2 block off one tank, pressurize it.
then block off the other, pressurize it.
that way i can join them and have 2 tanks fully pressurized (i dont have a really big compressor)

[schmanman]

what difference does it make If they are pressurised together, or separately, then? It would take the same amount of time, and cost more to do them separately.